CC chemokine receptor 2 (CCR2) is one of 19 members of the chemokine receptor subfamily of class A G-protein-coupled receptors (GPCRs). 

CCR2 is expressed in monocytes, immature dendritic cells, and T-cell subpopulations, and mediates acute inflammation by driving leukocyte migration to damaged or infected tissues towards chemokine ligands such as CCL2. Elevated expression of chemokines and their receptors such as CCR2 and its ligands can contribute to chronic inflammation and malignancy and hence these molecules are implicated in numerous inflammatory and neurodegenerative diseases including atherosclerosis, multiple sclerosis, asthma, neuropathic pain, and diabetic nephropathy, as well as cancer. These disease associations have motivated numerous studies in search of therapies that target the CCR2-chemokine axis^1,2.

As with most G-protein coupled receptors (GPCRs), chemokine receptors transmit signals across cell membranes by means of extracellular ligand and intracellular G-protein binding. CCR2 has seven transmembrane alpha helixes, and can take distinct conformational states that are necessary for chemokine/ligand binding, G-protein binding, activation, inactivation, and signal transmission³.

CCR2 can form homo- or heterodimers with other chemokine receptors. Homodimerization may be necessary for CCR2 chemotactic activity and occurs in the absence of the ligand. CCR2/CCR5 heterocomplexes activate calcium response and support cell adhesion rather than chemotaxis, whereas CCR2/CCR4 heterodimers have an allosteric trans-inhibitory effect on CCL2 binding².

CCR2 and its main ligand CCL2 are abundantly expressed in both the central and peripheral nervous system and have well established roles in osteoarthritis pain⁴, cerebral ischemia⁵, and depressive disorders⁶, among others.